<nav class="navbar navbar-expand-lg navbar-dark bg-dark">
  <div class="container">
    <a class="navbar-brand" href="#">后台管理系统</a>
  <button class="navbar-toggler" type="button" data-toggle="collapse" data-target="#navbarSupportedContent" aria-controls="navbarSupportedContent" aria-expanded="false" aria-label="Toggle navigation">
    <span class="navbar-toggler-icon"></span>
  </button>

  <div class="collapse navbar-collapse" id="navbarSupportedContent">
    <ul class="navbar-nav mr-auto">
      <li class="nav-item active">
        <a class="nav-link" href="{:url('admin/index/index')}"><i class="fa fa-home"></i>&nbsp;桌面</a> 
      </li>
       <li class="nav-item active">
        <a class="nav-link" href="{:url('admin/user/lis')}"><i class="fa fa-user"></i>&nbsp;学员管理</a> 
      </li>
      <li class="nav-item active">
        <a class="nav-link" href="{:url('admin/article/lis')}"><i class="fa fa-file-text"></i>&nbsp;文章管理</a> 
      </li>
      <li class="nav-item active">
        <a class="nav-link" href="{:url('admin/comment/lis')}"><i class="fa fa-comments"></i>&nbsp;评论管理</a> 
      </li>
      <li class="nav-item active">
        <a class="nav-link" href="{:url('admin/system/system')}"><i class="fa fa-cog"></i>&nbsp;系统管理</a> 
      </li>
    </ul>
   <ul class="navbar-nav">
      <li class="nav-item active">
        <a class="nav-link" href="#" style="position: relative;"><i class="fa fa-envelope-o fa-lg"></i><span class="badge badge-light" style="position: absolute;top: 0;right: 1px;">9</span></a>
      </li>
      <li class="nav-item dropdown">
        <a class="nav-link dropdown-toggle" href="#" id="navbarDropdown" role="button" data-toggle="dropdown" aria-expanded="false">
          admin
        </a>
        <div class="dropdown-menu" style="min-width: 1rem;" aria-labelledby="navbarDropdown">
          <a class="dropdown-item" href="#">个人信息</a>
          <div class="dropdown-divider"></div>
          <a class="dropdown-item" href="#">退出登录</a>
        </div>
      </li>
    </ul>
  </div>
  </div>
  
</nav>